North American Numbers Source-cited · ownership disclosed
Area code
512
In service
United States · since 1947

Austin

The original 1947 code for Austin and Central Texas. Now overlaid by 737; once covered much of south-central Texas before repeated splits.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Austin
Type
geographic
Status
in service
In service since
1947
Projected exhaust
2044 Q1

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 512 is

Central Texas: the greater Austin metropolitan area.

Communities served wholly or partly by 512:

AustinRound RockGeorgetownSan MarcosCedar ParkPflugervilleKyle

Representative; covers seven counties (Bastrop, Burnet, Caldwell, Hays, Travis, Milam, Williamson).

B · Relationships

How it relates to other codes

The codes 512 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Spawned · 1992 210 San Antonio Western portion including San Antonio split off as 210 in 1992.
Spawned · 1999 361 Corpus Christi Southern portion including Corpus Christi split off as 361 in 1999.
Overlay · 2013 737 Austin (overlay) 737 added as an Austin-area overlay in 2013.
What's changing. Active overlay with 737. Mandatory 10-digit dialing since June 2013.
C · History

How 512 got here

1947
Established as one of the original Texas area codes, covering a large south-central Texas region.
Source: Wikipedia (Area codes 512 and 737)
1992-11-01
Split; area code 210 carved off (San Antonio and the Rio Grande Valley).
Source: Wikipedia (Area codes 512 and 737)
1999-02-13
Split; area code 361 carved off (Corpus Christi / south).
Source: Wikipedia (Area codes 512 and 737)
2013-07-01
Area code 737 overlay went into service; 10-digit dialing mandatory since June 2013.
Source: Wikipedia (Area codes 512 and 737)
D · Capacity

How full it is

Prefixes assigned
800
Prefixes available
0
Thousands-blocks assigned
3,483

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 512 with another code →
Sources
Wikipedia ↗
Area codes 512 and 737
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.